2020 January 8
Galaxies in the River
Image Credit & Copyright: Star Shadows Remote Observatory, PROMPT, CTIO
Image Credit & Copyright: Star Shadows Remote Observatory, PROMPT, CTIO
Explanation:
Large galaxies grow by eating small ones.
Even our own galaxy engages in
a sort of galactic
cannibalism, absorbing small galaxies that are too close and
are captured by
the Milky Way's gravity.
In fact, the
practice is common
in the universe and illustrated by this striking pair of interacting
galaxies
from the banks of the southern constellation
Eridanus,
The River.
Located over 50 million light years away,
the large, distorted
spiral NGC 1532 is seen locked in a
gravitational struggle with dwarf galaxy NGC 1531 (right of center),
a struggle the smaller galaxy will
eventually lose.
Seen edge-on, spiral NGC 1532 spans about 100,000 light-years.
Nicely detailed in this sharp image, the
NGC 1532/1531 pair is thought to be similar
to the well-studied system of face-on spiral and small companion
known as M51.